Protective Panel Assembly And Method For Repairing Such A Protective Panel Assembly

ABSTRACT

The invention relates to a protective panel assembly and to a method for repairing an impact hole in the protective panel assembly. The protective panel assembly has three textile-reinforced concrete panels which are connected to one another via connecting elements to form a unit. The textile-reinforced concrete panels form an outer panel, an inner panel and an intermediate panel. Arranged between the outer panel and the intermediate panel is at least one fiber panel comprising fiber bundles of glass and/or aramid fibers incorporated in a synthetic matrix. An intermediate space exists between the intermediate panel and the inner panel. The intermediate space can be filled with air and/or a solid filler material which can be plastically and/or elastically deformed. Additional panels or layers can be omitted.

The invention relates to a protective panel assembly for protecting against gunfire and/or explosions, and to a method for repairing such a protective panel assembly after damage caused by an impact, for example by explosion fragments or a projectile.

Protective panel assemblies which are bullet-resistant exist in various embodiments. For example, WO 2009/111302 A2 describes a system comprising a cement-based protective panel. The protective panel has a cement core. Fiber-reinforced mats are adhesively bonded to opposite sides of the cement core. The three-layer protective panel can be arranged on a metal frame. It is also possible to arrange such three-layer protective panels on both sides of the frame.

The publication by K. H. Kyung and C. Meyer, “Aramid Fiber Mesh as Reinforcement of Concrete Panels Subjected to High Strain Rates”, Proc., 1st Int. Conf. On Textile Reinforced Concrete, Aachen, RILEM Publication S.A.R.L., Report PRO 50, September 2006 discloses a cement panel with aramid fiber reinforcement. A composite material panel composed of aramid fibers and cement can be arranged adjacent to this aramid-fiber-reinforced panel.

CN 201952936 U describes a protective panel assembly which has two steel-reinforced cement panels that are connected to one another by means of bolts. Mineral wool is arranged between the cement panels. A fiber panel comprising aramid or carbon fibers is arranged externally on one cement panel. The protective wall can be erected via a stand.

DE 20 2007 014 526 U1 describes a panel-shaped construction element made of concrete and concrete aggregate. A reinforcement mat comprising a plurality of fabric layers is embedded in the concrete material. A further layer composed of a castable, curable or settable material is arranged adjacent to said reinforced concrete layer. The two layers are mechanically anchored to one another.

US 2009/0282968 A1 describes a protective panel assembly having a plurality of aramid-fiber-reinforced panels which are embedded in a multilayer structure between a plurality of front panels and a plurality of back panels. The panel assembly is held together via a frame running peripherally in the circumferential direction.

A protective panel assembly comprising a plurality of layers is disclosed in US 2016/0102471 A1. Each layer is in turn of multilayer construction and may contain metal alloys, metal compositions, polymers, stone materials, fiber materials, and combinations thereof. The layers are held together by a frame arranged at the boundary.

A further protective panel assembly is known from US 2005/0139308 A1. The protective panel assembly comprises at least one alkali-resistant fiber layer which is embedded in an inorganic matrix. The resulting reinforcement panel is arranged on a carrier structure, for example a wall.

It can be regarded as an object of the present invention to create a protective panel assembly which presents a high degree of safety against explosions or gunfire and at the same time has a small thickness and a low weight per square meter. In particular, the protective panel assembly should be suitable as a wall element of a building or as a facing shell for attachment to façades.

This object is achieved by a protective panel assembly having the features of claim 1.

The protective panel assembly according to the invention has at least three and preferably precisely three textile-reinforced concrete panels: an outer panel, an inner panel, and an intermediate panel which is arranged between the outer panel and the inner panel. At least one textile layer is embedded in the concrete matrix of each concrete panel. Each textile layer is preferably formed by a mesh-type fabric composed of fiber bundles or filament bundles, wherein the bundles of the fabric extend either in a first direction or in a second direction. The concrete matrix may comprise for example cement and an aggregate and optionally concrete admixtures and/or concrete additives. The concrete panels are preferably oriented parallel to a panel plane that is defined by an x direction and a y direction of a Cartesian coordinate system.

The protective panel assembly additionally contains at least one fiber panel. If a plurality of fiber panels are present, these are arranged next to one another parallel to the panel plane, so that a normal vector of one fiber panel does not pass through the other fiber panels. The at least one fiber panel is arranged between the outer panel and the intermediate panel. The fiber panel comprises synthetic fiber bundles embedded in a synthetic matrix. The synthetic fibers or synthetic filaments may be made for example of aramid and/or glass and/or carbon. An epoxy resin for example may be used as the synthetic matrix.

The inner panel is arranged at a distance from the intermediate panel. An intermediate space is formed between the inner panel and the intermediate panel. The intermediate space may be filled with a gaseous and/or solid filler material. By way of example, the intermediate space may contain air and/or a solid insulation material, such as for example polystyrene, mineral wool, natural fibers, etc.

The panels of the protective panel assembly are connected to one another via connecting elements and thus form a cohesive assembly or a composite. The connecting elements have a first end and a second end which is located opposite the first end. The two ends of a connecting element are embedded in different textile-reinforced concrete panels and are fastened or bound thereto by a form fit and/or in a materially bonded manner. One connecting element may connect for example the outer panel and the intermediate panel. One connecting element may also connect the intermediate panel to the inner panel. It is also possible that one connecting element extends from the first end in the outer panel through the intermediate panel to the second end in the inner panel and thus connects all three textile-reinforced concrete panels to one another. By way of the connecting elements, the inner panel can be kept at a distance from the intermediate panel so as to form the intermediate space.

A side of the outer panel facing away from the fiber panel forms the outer side of the protective panel assembly. The side of the inner panel facing away from the intermediate panel forms the inner side of the protective panel assembly. If an impacting element, such as for example a projectile or an explosion fragment or the like, impinges on the outer side, the impacting element is first deformed. Depending on the energy of the impacting element, it may pass through the outer panel and then impinges on the fiber panel. The remaining energy of the deformed impacting element is converted there into a stretching and straining of the fibers. Part of the fiber panel may deform in the direction of the intermediate panel. This deformation can lead to the situation whereby, on the side of the intermediate panel opposite the fiber panel, parts of the concrete material spall and are thrown toward the inner panel. These spalled parts may traverse the intermediate space and then possibly impinge on the inner panel. The energy of these spalled concrete parts of the intermediate panel is low enough that, although they may still cause a little damage on the side of the inner panel facing toward the intermediate space, nevertheless no further concrete parts spall on the inner side of the concrete panel assembly. The ductility of the three textile-reinforced concrete panels in conjunction with the fiber panel prevents any spalling of the concrete material on the inner side. People or equipment located behind the inner side are thereby effectively protected against explosions or gunfire.

Since the textile-reinforced concrete panels are connected to one another via the connecting elements and the at least one fiber panel is held between the outer panel and the inner panel, a composite system is created which in static terms can be regarded as a single element, thereby simplifying static calculations on buildings. The textile-reinforced concrete panels have a high degree of ductility, which in collaboration with the at least one fiber panel greatly improves the protection against impacting elements. The protective panel assembly can be configured with a much smaller thickness and/or much lower weight than other known protective panel systems.

In one embodiment, the protective panel assembly may comprise only the three textile-reinforced concrete panels and the fiber panel.

If, in one variant embodiment, a solid filler material is arranged in the intermediate space instead of air, said solid filler material being used in particular in a cohesive panel-like form, then the production of the protective panel assembly and in particular the casting of the individual textile-reinforced concrete panels can be simplified.

In one advantageous embodiment, the at least one fiber panel may bear with one side directly against the outer panel and/or with the respective other side directly against the intermediate panel. Further intermediate layers between the outer panel and the intermediate panel are not necessary. The fiber panel may in this case be connected to the outer panel and/or to the intermediate panel before the concrete sets. The outer panel and the intermediate panel may also comprise a unitary concrete matrix.

Preferably, the at least one connecting element does not pass through the at least one fiber panel and/or the connecting elements are not incorporated in the synthetic matrix of the fiber panels. A connecting element which is embedded with a first end in the concrete matrix of the outer panel preferably extends past the at least one fiber panel and/or extends through between two or more adjacent fiber panels. If a plurality of fiber panels are arranged next to one another between the outer panel and the intermediate panel, the distance between the fiber panels is kept as small as possible so as not to form any weak points. It is also possible that a fiber panel has a cutout for an associated connecting element, wherein the cutout may also be arranged in the edge side. Only in the region of the cutout or the connecting element do the two immediately adjacent fiber panels then not butt directly against one another without a gap. Since no connecting element is incorporated in the at least one fiber panel, the fiber panels can be pre-manufactured and transported to the construction site in order to produce the protective panel assembly.

A connecting element which is embedded with a first end in the concrete of the outer panel preferably does not pass through the outer side of the protective panel assembly. Alternatively or in addition, a connecting element which is embedded with its second end in the concrete of the inner panel does not pass through the inner side of the protective panel assembly. The outer side and the inner side can thus be formed of a uniform material surface in an uninterrupted fashion.

In one preferred embodiment, the at least one connecting element has a connecting web which connects the first end of the connecting element to the second end of the connecting element. In each case a transverse web may be provided at the first end and/or at the second end. In order to connect all three textile-reinforced concrete panels, the connecting web may completely pass through the intermediate panel.

In order to conduct the energy acting on the outer side only partially to the intermediate panel and/or to the inner panel via the connecting web, the connecting web may, at least in one section, run in a manner inclined by an angle of inclination relative to a cross-sectional plane, wherein the cross-sectional plane is oriented at right angles to the panel plane and/or to the outer panel and/or to the intermediate panel and/or to the inner panel. It is also possible to provide a plurality of sections of the connecting web at different inclinations or angles of inclination. It is thus possible to diminish the direct introduction of a force via the connecting web from the outer panel into the intermediate panel or the inner panel parallel to the cross-sectional plane.

In addition or as an alternative, it is also possible in one exemplary embodiment to configure the connecting web to be weaker and/or to have a smaller thickness than the other component parts of the connecting element and in particular than the transverse web which may be present at the first end and/or at the second end of the connecting element.

The connecting element may be formed by a fiber-reinforced composite material. In order to weaken the connecting web, the number and/or density of the fibers or fiber bundles may be lower in the connecting web than in the at least one transverse web or in other component parts of the connecting element.

In one exemplary embodiment, the connecting elements form a plurality of groups and for example two groups. One group contains at least one first connecting element, and the other group contains at least one second connecting element. The at least one first connecting element is offset from the at least one second connecting element in the panel plane, that is to say in the x direction and/or y direction.

The at least one first connecting element may connect the outer panel to the intermediate panel. The at least one second connecting element may connect the intermediate panel to the inner panel. Continuous connecting elements which extend from the outer panel through the intermediate panel to the inner panel are preferably not provided in this embodiment.

Each of the concrete panels has at least one textile layer. The number of textile layers in the intermediate panel is preferably greater than in the outer panel and/or in the inner panel. In one exemplary embodiment, the intermediate panel may have at least three textile layers. In one exemplary embodiment, the outer panel and/or the inner panel may each have precisely one textile layer. If a concrete panel has more than one textile layer, these are preferably arranged at a distance from one another in a z direction at right angles to the panel plane. The z direction corresponds to the spatial direction in which the normal vector of the relevant concrete panel points.

As already explained, a textile layer is preferably formed by a mesh-type fabric composed of fiber bundles. The first fiber bundles extend at a distance from one another in the x direction, and the other fiber bundles extend for example at a distance from one another in the y direction. The fibers or filaments of each fiber bundle are stretched as far as possible. The intersecting fiber bundles may be connected to one another at the points of intersection, for example by a connecting thread or the like, before being embedded in the concrete matrix.

The invention additionally relates to a method for repairing an impact hole in the protective panel assembly described above. In said method, the following steps are carried out:

First, an area of the impact hole extending in the intermediate panel is filled with a resin or a resin is pressed into said area. A replacement piece for the fiber panel is then inserted into the impact hole on the existing fiber panel. The area of the fiber panel damaged by the impacting element is covered by the replacement piece. The area of the impact hole extending in the outer panel is then filled with a body filler.

Advantageous embodiments of the invention will become apparent from the dependent claims, from the description and from the drawings. Preferred exemplary embodiments of the invention will be explained in detail below with reference to the appended drawings. In the drawings:

FIG. 1 shows a schematic cross-sectional view through one exemplary embodiment of a protective panel assembly,

FIG. 2 shows a schematic cross-sectional view through a further exemplary embodiment of a protective panel assembly,

FIG. 3a shows a schematic cross-sectional view through one exemplary embodiment of a fiber panel of the protective panel assembly,

FIG. 3b shows a schematic illustration of the fibers or fiber bundles of a fiber panel of the protective panel assembly,

FIG. 4 shows a schematic perspective diagram of the structure of an exemplary connecting element of the protective panel assembly,

FIG. 5 shows a schematic view of a fiber bundle fabric for incorporation in a concrete matrix of a concrete panel of the protective panel assembly as textile reinforcement,

FIG. 6 shows a schematic plan view of the outer side of a protective panel assembly,

FIG. 7 shows a schematic cross-sectional view of a further exemplary embodiment of a protective panel assembly,

FIG. 8 shows a schematic cross-sectional view of a further exemplary embodiment of a protective panel assembly,

FIGS. 9-11 show different embodiments of connecting elements for use in the protective panel assembly,

FIGS. 12-14 each show a schematic cross-sectional view through an exemplary embodiment of a protective panel assembly showing individual steps for repairing an impact hole.

The invention provides a protective panel assembly 20 for protecting against gunfire and/or explosions. The protective panel assembly 20 has three textile-reinforced concrete panels 21: an outer panel 22, an inner panel 23 and an intermediate panel 24. The concrete panels 21 are oriented substantially parallel to one another. Each concrete panel 21 extends parallel to a panel plane that is defined by an x direction and a y direction of a Cartesian coordinate system. As viewed in a z direction of the Cartesian coordinate system, the intermediate panel 24 is arranged between the outer panel 22 and the inner panel 23. The three textile-reinforced concrete panels 21 do not bear directly against one another but rather are each arranged at a distance from one another in the z direction.

In the exemplary embodiment, the thickness of the intermediate panel 24 is greater than the thickness of the outer panel 22 and/or of the inner panel 23. Preferably, the thickness of the intermediate panel 24 is at least twice as great as that of the outer panel 22 and/or of the inner panel 23.

A side of the outer panel 22 facing away from the intermediate panel 24 forms an outer side 25 of the protective panel assembly 20. The inner panel 23 has a side facing away from the intermediate panel 24 that forms an inner side 26 of the protective panel assembly 20. People or equipment to be protected are located behind the inner side 26. Impacting elements, such as fragments, projectiles or the like, impinge on the outer side 25 of the protective panel assembly 20.

Each textile-reinforced concrete panel 21 has at least one textile layer 30 which is embedded in a concrete matrix 31. If a textile-reinforced concrete panel 21 has more than one textile layer 30, the individual textile layers are arranged at a distance from one another in the z direction. The individual textile layers 30 preferably do not touch one another. As the thickness of a concrete panel 21 in the z direction increases, the number of textile layers 30 increases and preferably increases in a manner proportional to the thickness. In the preferred exemplary embodiment described here, the outer panel 22 and the inner panel 23 each have a single textile layer 30. The number of textile layers 30 of the intermediate panel 24 is for example greater than the number of textile layers of the outer panel 22 and/or of the inner panel 23. In the exemplary embodiments illustrated here, at least three textile layers 30 are embedded in the concrete matrix 31 in the intermediate panel 24.

The concrete matrix 31 consists of a binder, such as for example cement, and an aggregate. As the aggregate, use may be made for example of gravel and/or sand. The concrete matrix may additionally contain concrete admixtures or concrete additives.

The structure of a textile layer 30 is illustrated schematically in FIG. 5. The textile layer 30 is formed by fiber bundles 32 arranged in a mesh-like manner. A first group 33 of fiber bundles 32 extends in one direction, for example in the x direction, while a second group 34 of fiber bundles 32 extends in another direction, for example in the y direction. The two groups 33, 34 are placed one on top of the other and thereby form a mesh-type fabric. The fiber bundles 32 run in a substantially rectilinear manner.

In the exemplary embodiment, substantially rectangular and/or square meshes are formed in the fabric. Alternatively, the meshes could also be diamond-shaped. It is also possible to add at least one further group of fiber bundles 32, so that the fabric consists of three or more groups of fiber bundles 32 arranged one on top of the other. The fiber bundles 32 of a common group 33, 34 extend substantially parallel to one another in each case. At the points of intersection, the intersecting fiber bundles are connected to one another by connecting means, for example by connecting threads or the like. The fabric, which is flexible before being incorporated in the concrete matrix 31, is thus able to be handled and the positioning of the individual fiber bundles 32 is retained.

Suitable materials for the fibers of the fiber bundles 32 of the textile layer 30 are for example filaments made of glass, carbon, or other filaments suitable for textile concrete.

Compared to steel concrete, the textile-reinforced concrete panels 21 have a greater degree of ductility and a low weight. Due to this ductility, a breaking of the outer panel 22 by impacting elements takes place only under greater forces or loads compared to steel concrete.

The three textile-reinforced concrete panels 21 are connected to one another via connecting elements 40. In the exemplary embodiment shown in FIG. 1, all the connecting elements 40 are configured in an identical manner. Each connecting element 40 has a first end 41 and an opposite second end 42. A transverse web 43 is provided at each of the two ends 41, 42. The transverse webs 43 extend in the x direction and in the y direction and may be formed by plate-shaped sections of the connecting element 40. The two transverse webs 43 are connected to one another via a connecting web 44 which extends from the first end 41 to the second end 42. In the exemplary embodiment of the protective panel assembly 20 illustrated in FIG. 1, the connecting web 44 runs parallel to a cross-sectional plane E that is defined by the z direction and the y direction. The two transverse webs 43 extend at right angles thereto.

A transverse web 43 may extend from the connecting web 44 in the x direction on just one side or on both sides. As a result, it is possible to form for example connecting elements 40 which are U-shaped, J-shaped, C-shaped, T-shaped or double-T-shaped as seen in cross-section.

The connecting elements 40 pass through neither the outer side 25 nor the inner side 26 of the protective panel assembly 20.

The structure of an exemplary connecting element 40 is illustrated schematically in FIG. 4. The connecting element 40 is formed of fiber bundles 45 embedded in a synthetic matrix. In FIG. 4, the fiber bundles 45 are each illustrated by a line. In a manner analogous to the mesh-type fabric of a textile layer 30, the fiber bundles 45 in each case form at least two groups which are placed one on top of the other in different directions in order to form the mesh structure. Fiber bundles 45 thus arranged in the form of a mesh are embedded in a synthetic matrix and brought into the desired shape. In doing so, a plurality of mesh parts 46 may be formed and may be connected to one another by means of the synthetic matrix, as illustrated schematically in FIG. 4. As shown in FIG. 4, the two mesh parts 46 have sections arranged parallel to one another, which sections are placed one on top of the other and are connected via the synthetic matrix. In the exemplary embodiment, these sections form the connecting web 44. Sections of each mesh part 46 which are angled away therefrom form the transverse webs 43 at the first end 41 and/or at the second end 42. In order to achieve the desired shape of the connecting element 40, the mesh parts 46 which are connected to one another may also have other shapes differing from FIG. 4.

The fiber bundles 45 of the connecting element 40 may be formed for example by glass fibers. Preferably, the fiber bundles 45 are incorporated in a matrix of epoxy resin or are impregnated in an epoxy resin. The epoxy resin also serves as a connecting means for connecting a plurality of mesh parts 46 in a materially bonded manner.

As a modification to the described exemplary embodiment, it is also possible that a connecting element 40 is formed of a single mesh part 46.

At least one fiber panel 50 is arranged between the outer panel 22 and the intermediate panel 24. The at least one fiber panel 50 bears for example with one side against the outer panel 22 and with the opposite side against the intermediate panel 24 and/or is connected to the outer panel 22 and/or to the intermediate panel 24. By way of example, the at least one fiber panel 50 may be connected to the respective concrete panel 21 through contact with the concrete matrix 31 of the outer panel 22 and/or of the intermediate panel 24 and subsequent curing of the concrete matrix 31.

If a plurality of fiber panels 50 are provided, these extend next to one another in a common plane and are not offset from one another in the z direction. In the exemplary embodiment, the connecting elements 40 do not pass through the at least one fiber panel 50. The connecting elements 40 extend past the at least one fiber panel 50. Alternatively, it is also possible to provide a corresponding cutout in a fiber panel 50 for the passage of the respective connecting element 40. A further possibility lies in providing a cutout for the connecting web 44 in the edge of a fiber panel 50, so that immediately adjacent fiber panels 50 can bear directly against one another at the locations at which no connecting web 44 and no connecting element 40 are present.

As can be seen schematically in FIG. 6, the connecting elements 40 do not extend over the entire dimension of the protective panel assembly 20 in the x direction and in the y direction. Two adjacently arranged fiber panels 50 can therefore bear against one another next to the connecting elements 40, as viewed in the y direction. A corresponding cutout may be provided in one or in both adjacent fiber panels 50 in the region of the connecting web 44. The number of fiber panels 50 may vary depending on the number of connecting elements 40 used and on the position thereof. Three fiber panels arranged next to one another in the x direction are illustrated in FIG. 6, with a respective connecting element 40 or connecting web 44 extending through between said fiber panels.

The at least one fiber panel 50 comprises synthetic fiber bundles 51 which are connected to one another and in particular are connected to one another by weaving, said synthetic fiber bundles being made of glass fibers and/or aramid fibers. The connection by weaving can be selected at will. A fabric 52 which has for example a plain weave is illustrated in FIG. 3b . The fabric 52 composed of synthetic fiber bundles 51 is embedded in a synthetic matrix 53 of the fiber panel 50 (FIG. 3a ). For the fiber panel 50, it is essential that the synthetic fibers or synthetic fiber bundles 51 bear very tightly against one another and no intermediate spaces or only very small intermediate spaces remain. An epoxy resin is preferably used as the synthetic matrix 53. The synthetic fiber bundles 51 and for example the aramid fiber bundles or glass fiber bundles are protected by way of the synthetic matrix 53 against destruction of or damage to the adjacent concrete panels 21 caused by the alkaline concrete matrix 31.

An intermediate space 57 is formed between the intermediate panel 24 and the inner panel 23. In the z direction, the inner panel 23 is arranged at a distance from the intermediate panel 24. At least some of the provided connecting elements 40 pass through this intermediate space 57. Apart from that, the intermediate space 57 can be filled with air (FIG. 2) and/or a solid and preferably sheet-like or mat-like filler material 58 (for example FIG. 1). The filler material 58 is elastically and/or plastically deformable and in particular is much easier to deform than all the other panels 21, 50 of the protective panel assembly 20. Suitable filler materials are for example the insulating materials that are usually used. As the filler material 58, use may be made for example of polystyrene sheets, natural and/or synthetic fiber mats, mineral wool mats, etc. In principle, it is alternatively also possible to use loose bulk material as the filler material 58. However, cohesive sheets or mats which form the filler material 58 are easier to handle during production and are therefore preferred.

The protective panel assembly 20 described above and shown in FIGS. 1 and 2 acts as follows:

When an impacting element impinges on the outer side 25, the impacting element is first deformed by the outer panel 22, as a result of which the kinetic energy is reduced. The impacting element may completely pass through the outer panel 22 and may impinge on the fiber panel 50. There, the impacting element deforms the aramid or glass fibers, as a result of which the kinetic energy is reduced through stretching and deformation of the fibers of the synthetic fiber bundles 51. The fiber panel 50 is damaged and/or deformed in the area of the impact hole. The impacting element may penetrate into the intermediate panel 24. As a result of this impact in the intermediate panel 24, concrete parts may spall on the side of the intermediate panel 24 facing toward the inner panel 23. Such a spalled concrete part may enter the intermediate space 57 or pass through the latter and impinge on the inner panel 23. Due to the size, shape and reduced energy of such a spalled concrete part, damage may possibly still occur on the side of the inner panel 23 facing toward the intermediate space 57 but the impact energy is not sufficient for concrete parts to be thrown onto the inner side 26 of the protective panel assembly 20, which could injure or damage people or equipment.

In the exemplary embodiments in FIGS. 1 and 2, a connecting element 40 connects all three textile-reinforced concrete panels 21 to one another. As a modification thereto, it is provided in the exemplary embodiment illustrated in FIG. 7 that the connecting elements 40 are subdivided into a group of first connecting elements 40 a and a group of second connecting elements 40 b. By way of example, the first and second connecting elements 40 a, 40 b are U-shaped or bracket-shaped as seen in cross-section. The first end 41 of the first connecting elements 40 a is embedded in the concrete matrix 31 of the outer panel 22, and the second end 42 of said first connecting elements 40 a is embedded in the concrete matrix 30 of the intermediate panel 24. In contrast, the first end 41 of the second connecting elements 40 is embedded in the concrete matrix 31 of the intermediate panel 24, and the second end 42 is embedded in the concrete matrix 31 of the inner panel 23. Therefore, the first connecting elements 40 a connect the outer panel 22 to the intermediate panel 24, and the second connecting elements 40 b connect the intermediate panel 24 to the inner panel 23. The second connecting elements 40 b are offset from the first connecting elements 40 a in the x direction and/or y direction. As a result, the connecting webs 44 of the first connecting elements 40 a are not aligned with the connecting webs 44 of the second connecting elements 40 b. A force or pressure wave acting on the outer side 25 will thus not be conducted via the connecting elements 40 a, 40 b and in particular the connecting webs 44 into the inner panel 23. The risk that concrete parts may spall on the inner side 26 and may injure or damage people or equipment is thereby further reduced.

The design or shape of the first and second connecting elements 40 a, 40 b in FIG. 7 may also correspond to the connecting elements 40 shown in FIGS. 1 and 2. Other embodiments of the first and second connecting elements 40 a, 40 b are also possible, as has been explained above. The structure of the protective panel assembly 20 shown in FIG. 7 otherwise corresponds to the structure of the exemplary embodiments explained above.

A further modified embodiment of the protective panel assembly 20 with altered connecting elements 40 is illustrated in FIG. 8. Apart from the connecting elements 40, this exemplary embodiment corresponds to the embodiment shown in FIG. 1 or 2. The difference of the exemplary embodiment shown in FIG. 8 from FIGS. 1 and 2 lies in the fact that the connecting webs 44 of the connecting elements 40 run obliquely or in an inclined manner relative to the cross-sectional plane E, which is oriented at right angles to the X direction and thus passes through the panels 21, 50 of the protective panel assembly 20 at right angles. An angle of inclination α relative to the cross-sectional plane E is in this case greater than 0 degrees and less than 90 degrees and in particular less than 80 degrees or less than 70 degrees. The angle of inclination α is preferably at least 10 degrees or 15 degrees or 25 degrees. A force Fz acting along the cross-sectional plane E or in the z direction in the region of the connecting web 44 on the first end 41 is thereby transmitted only partially along the connecting web 44 to the inner panel 23. A smaller longitudinal force Fs acts along the connecting web 44, and in addition a transverse force Fq acts at right angles to the connecting web 44. The vector breakdown of the forces is illustrated schematically in FIG. 9. As a result, the force transmission through the connecting web 44 between the first end 41 and the second end 42 can be reduced. The greater the angle of inclination α, the smaller the magnitude of the longitudinal force Fs. The magnitude of the transverse force Fq is less relevant since this transverse force Fq does not lead to spalling on the inner side 26 of the protective panel assembly 20.

As shown in FIGS. 8 and 9, the entire connecting web 44 extends in a correspondingly inclined plane from the first end 41 to the second end 42. As an alternative, it is also possible to incline just one section of the connecting web 44 at an angle of inclination α relative to the cross-sectional plane E. A further possibility lies in providing a plurality of differently inclined sections of the connecting web 44, as illustrated schematically in FIG. 11. In said figure, a first section 44 a of the connecting web 44 is inclined at a first angle of inclination α1 and a second section 44 b of the connecting web 44 is inclined at a second angle of inclination α2 relative to the cross-sectional plane E. The two sections 44 a, 44 b form a kink 62. More than two sections could also adjoin one another in a concertina-like or zigzag-like manner between the transverse web 43 at the first end 41 and the transverse web 43 at the second end 42. The values of the first angle of inclination α1 and of the second angle of inclination α2 may be identical or different.

FIGS. 10 and 11 show an alternative or further possibility of reducing the maximum force that can be transmitted from the first end 41 to the second end 42, by reducing the stability of the connecting web 44. This can be achieved for example in that the wall thickness ws of the connecting web 44 is smaller at least in some regions than the maximum wall thickness wq of the transverse webs 43. In addition or as an alternative, the weakening of the connecting web 44 can also be achieved by reducing the density of the fiber bundles 45 or fibers within the fiber bundles 45 compared to the other parts of the connecting element 40.

Based on the exemplary embodiment of the protective panel assembly 20 shown in FIG. 1, FIGS. 12-14 illustrate an exemplary embodiment of a method for repairing an impact hole 65.

FIG. 12 shows the impact hole 65 following the impact of an element, for example a projectile 66. The projectile 66 has stretched individual filaments 67 of the synthetic fiber bundles 51 out of the fiber panel 50 and has moved them into the intermediate panel 24 in an area of the impact hole 65. On the side of the intermediate panel 24 facing toward the intermediate space 57, a part 68 has spalled in the direction of impact and has deformed the filler material 58 in the intermediate space 57. For repair purposes, the procedure is as follows:

First, the area of the impact hole 65 located in the intermediate panel 24 is filled with a resin 69 by pressing in the resin 69. A replacement piece 70 which has been cut to fit is then used for the fiber panel 50. The replacement piece 70 comprises synthetic fibers embedded in a synthetic matrix and preferably has the same structure as the fiber panel 50. The replacement piece 70 can be taken from a replacement fiber panel by cutting out a suitable piece and can be applied to the part of the fiber panel 50 that is arranged within the impact hole 65. The resin 69 or another connecting means can be used to connect the replacement piece 70 to the fiber panel 50. These repair steps are illustrated schematically in FIG. 13.

Finally, the area of the impact hole 65 in the outer panel 22 is filled with a body filler 71 and is made substantially level with the outer surface 25 (FIG. 14).

The invention relates to a protective panel assembly 20 and to a method for repairing an impact hole 65 in the protective panel assembly 20. The protective panel assembly 20 has three textile-reinforced concrete panels 21 which are connected to one another via connecting elements 40 to form a unit. The textile-reinforced concrete panels 21 form an outer panel 22, an inner panel 23 and an intermediate panel 24. Arranged between the outer panel 22 and the intermediate panel 24 is at least one fiber panel 50 comprising fiber bundles 51 of glass and/or aramid fibers incorporated in a synthetic matrix 53. An intermediate space 57 exists between the intermediate panel 24 and the inner panel 23. The intermediate space 57 can be filled with air and/or a solid filler material 58 which can be plastically and/or elastically deformed. Additional panels or layers can be omitted.

LIST OF REFERENCE SIGNS

-   20 protective panel assembly -   21 textile-reinforced concrete panel -   22 outer panel -   23 inner panel -   24 intermediate panel -   25 outer side -   26 inner side -   30 textile layer -   31 concrete matrix -   32 fiber bundle -   33 first group -   34 second group -   40 connecting element -   40 a first connecting element -   40 b second connecting element -   41 first end -   42 second end -   43 transverse web -   44 connecting web -   44 a first section of the connecting web -   44 b second section of the connecting web -   45 fiber bundle -   46 mesh part -   50 fiber panel -   51 synthetic fiber bundle -   52 fabric -   53 synthetic matrix -   57 intermediate space -   58 filler material -   62 kink -   65 impact hole -   66 projectile -   67 synthetic fiber -   68 part of the concrete matrix -   69 resin -   70 replacement piece -   71 body filler -   α angle of inclination -   α1 first angle of inclination -   α2 second angle of inclination -   E plane -   Fz acting force -   Fq transverse force -   Fs longitudinal force -   wq maximum wall thickness of the transverse webs -   ws wall thickness of the connecting web -   x x direction -   y y direction -   z z direction 

1. A protective panel assembly (20) for protecting against gunfire and/or explosions, the assembly comprising: at least three textile-reinforced concrete panels (21) which form an outer panel (22), an inner panel (23) and an intermediate panel (24), at least one fiber panel (50) which comprises synthetic fiber bundles (51) embedded in a synthetic matrix (53), wherein the at least one fiber panel (50) is arranged between the outer panel (22) and the intermediate panel (24), a plurality of connecting elements (40) having a first end (41) embedded in a concrete matrix (31) of one of the textile-reinforced concrete panels (21) and having a second end (42) embedded in a concrete matrix (31) of another of the textile-reinforced concrete panels (21), wherein the inner panel (23) is arranged at a distance from the intermediate panel (24) so as to form an intermediate space (57).
 2. The protective panel assembly according to claim 1, wherein the at least one fiber panel (50) has opposing sides and abuts with one side directly against the outer panel (22) and with the other side directly against the intermediate panel (24).
 3. The protective panel assembly according to claim 1, wherein one of the plurality of connecting elements (40) is embedded with the first end (41) thereof in a concrete matrix (31) of the outer panel (22) and extends past the at least one fiber panel (50).
 4. The protective panel assembly according to claim 1, wherein one of the plurality of connecting elements (40) is embedded with the first end (41) thereof in a concrete matrix (31) of the outer panel (22) and does not pass through an outer side (25) of the protective panel assembly (20).
 5. The protective panel assembly according to claim 1, wherein one of the plurality of connecting elements (40) is embedded with its second end (42) in a concrete matrix (31) of the inner panel (23) and does not pass through an inner side (26) of the protective panel assembly (20).
 6. The protective panel assembly according to claim 1, wherein at least one of the plurality of connecting elements (40) has a connecting web (44) which connects the first end (41) to the second end (42) thereof and completely passes through the intermediate panel (24).
 7. The protective panel assembly according to claim 6, wherein the connecting web (44) includes at least one section (44 a, 44 b) that extends in an inclined manner by an angle of inclination (α, α1, α2) relative to a plane (E) that is oriented at a right angle to at least one of the outer panel (22), the intermediate panel (24), or the inner panel (23).
 8. The protective panel assembly according to claim 1, wherein the at least one of the plurality of connecting elements (40) has a transverse web (43) at at least one of the first end (41) and the second end (42).
 9. The protective panel assembly according to claim 7, wherein the at least one of the plurality of connecting elements (40) has a transverse web (43) at at least one of the first and second ends (41, 42), and the connecting web (44) is configured to be weaker than the transverse web (43).
 10. The protective panel assembly according to claim 1, wherein the plurality of connecting elements (40) include at least one first connecting element (40 a) and at least one second connecting element (40 b) which are arranged in an offset manner with respect to one another in at least one of two spatial directions (x, y) that define a plane arranged parallel to the outer panel (22).
 11. The protective panel assembly according to claim 10, wherein the at least one first connecting element (40 a) connects the outer panel (22) to the intermediate panel (24), and the at least one second connecting element (40 b) connects the intermediate panel (24) to the inner panel (23).
 12. The protective panel assembly according to claim 1, wherein the plurality of connecting elements (40) respectively comprise fiber bundles (45) embedded in a synthetic matrix.
 13. The protective panel assembly according to claim 1, wherein individual ones of the textile-reinforced concrete panels (21) have at least one textile layer (30) which is formed by a mesh-type fabric composed of fiber bundles (32).
 14. The protective panel assembly according to claim 13, wherein the intermediate panel (24) has at least three textile layers (30) including the at least one textile layer which are embedded at a distance from one another in a concrete matrix (31) of the intermediate panel (24).
 15. The protective panel assembly according to claim 13, wherein a number of textile layers (30) in the intermediate panel (24) is greater than in the outer panel (22) and/or in the inner panel (23).
 16. The protective panel assembly according to claim 1, wherein the intermediate space (57) is filled with a solid filler material (58).
 17. The protective panel assembly according to claim 16, wherein the filler material (58) is elastically and/or plastically deformable.
 18. A method for repairing a protective panel assembly (20) according to claim 1 which has an impact hole (65) extending into the outer panel, the fiber panel, and the intermediate panel, said method comprising: filling an area of the impact hole (65) in the intermediate panel (24) with a resin (69), inserting a replacement fiber panel piece (70) for the fiber panel (50) into the impact hole (65) in the existing fiber panel (50), filling an area of the impact hole (65) in the outer panel (22) with a body filler (71). 